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authorPali Rohár <pali.rohar@gmail.com>2015-06-23 10:11:19 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-08-03 09:29:16 -0700
commit4e5c0806a19975c7d9ab9171af53d4e8125342aa (patch)
tree710dec624b8dd3add544dd44ecd4073e4fe9b114
parenta35b0d6cc0ec26fb607f6cf7bc7be5756c5de63e (diff)
dell-laptop: Fix allocating & freeing SMI buffer page
commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream. This commit fix kernel crash when probing for rfkill devices in dell-laptop driver failed. Function free_page() was incorrectly used on struct page * instead of virtual address of SMI buffer. This commit also simplify allocating page for SMI buffer by using __get_free_page() function instead of sequential call of functions alloc_page() and page_address(). Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/platform/x86/dell-laptop.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index d688d806a8a5..2c1d5f5432a9 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -305,7 +305,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
};
static struct calling_interface_buffer *buffer;
-static struct page *bufferpage;
static DEFINE_MUTEX(buffer_mutex);
static int hwswitch_state;
@@ -1896,12 +1895,11 @@ static int __init dell_init(void)
* Allocate buffer below 4GB for SMI data--only 32-bit physical addr
* is passed to SMI handler.
*/
- bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
- if (!bufferpage) {
+ buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
+ if (!buffer) {
ret = -ENOMEM;
goto fail_buffer;
}
- buffer = page_address(bufferpage);
ret = dell_setup_rfkill();
@@ -1965,7 +1963,7 @@ fail_backlight:
cancel_delayed_work_sync(&dell_rfkill_work);
dell_cleanup_rfkill();
fail_rfkill:
- free_page((unsigned long)bufferpage);
+ free_page((unsigned long)buffer);
fail_buffer:
platform_device_del(platform_device);
fail_platform_device2: